A replicating technique for teeth and restorations was developed and evaluated over the past project period. The technique utilizes a polyether impression which is cast into epoxy positive replicas for SEM evaluation. The technique has been used to reproduce etched enamel in clinical patients and to show changes in amalgam restorations placed in dogs with excellent duplication of the subject. These techniques will be applied to the study of time dependent morphological changes of etched enamel, amalgam restorations, composite restorations, evaluation of orthodontic bracketing procedures, and plaque accumulation. All studies will be conducted on clinical patients.